Electric zinc-furnace with integral condenser.



J'. THOMS[)N ELECTRIC ZINC FURNACE WITH INTEGRAL CONDENSER.

' APPLICATION FILED JAN. 2, 1913.

1,080,866. PatentedDec. 9, 1913.

3 SHEETS-SHEET"! Vii/1655652 v 2" J. THOMSON; ELECTRIC ZINC FURNACE WITH INTEGRAL CONDENSER.

APPLICATION FILED JAN. 2. 1913.

Patentd Dec. 9, 1913.-

s SHEETSSEEET 2.

I WIT/165555;

J. THOMSON.

ELEC RIG ZINC FURNACE WITH INTEGRAL CONDENSER.

' APPLICATION FILED JAN. 2, 1013,

1,080,866, Patented Dec. 9, 19 125.

3 SHEETS-SHEET 3.

CQLAHWZ;

JOHN THOMSON, OF NEW YORK, N. Y.

ELECTRIC ZINC-FURNACE WITH INlEGR-AL CONDENSER.

Specification of Letters Patent.

Patented Dec. 9,1913.

Application filed January 2, 1913. Serial Nata 3,785.

To all whomz't may concern:

Beit known that I. JOHN THOMSON, a.

citizen of the United States, and a resident of the borough of Manhattan of the city of New York, in the county and State of New York, have invented certain new and useful Improvements in Electric Zinc-Furnaces with Integral Condensers, of which the following is a specification, reference being made to the accompanying drawings, forming a parthereof.

This invention relates to the metallurgy ofzinc having for its object the production of Zinc-fume .which is subsequently condensed to liquid metal.

A. description ofthe particular means for attaining the desired results and such an elucidation of thegeneral principles applicable thereto as will provide a complete disclosure of the invention will be .concurrently pointed out in connection with the description of the accompanying drawings; which represent certain embodiments of the invention.

Figure 1 is a transverse center section of the furnace; Fig. 2, on the right hand side of its center line, is a top plan view, while on the left hand side it is a horizontal section, as on the plane A, A, and Fig. 3 is also a transverse center section of the furnace showing modifications in construction.

This'furnace is particularly intended for the reduction of oxid of zinc combined With carbon as the reagent whereby, when adequately heated, the following representative reaction ensues, namely:

'If pure ZnO and C are used in precise correct relative proportions then the answer of the above formula is an exact expression Such conditions, howless inert residual matter will remain, depending upon the purity of the materials employed and hence the formula becomes simply representative as above stated. The presence of this residual matter is a cause of difiiculty in realizing a'succcssful result.

The heat necessary for decomposing the charge is preferably derived by direct conduction or by radiation or by both from a in which case there obtain in commercial practice exposed portions of the resistor.

' resistor H formed of a bed of broken carbon, interpolated between terminals as 3, 3, suitably connected to a source of electric energy. The resistor is supported by a series of grate bars 4%, spaced as 5, and rest upon brick ledges 6. The longitudinal sides of the resistor are .preferably confined by rows of vertical rods 7, spaced as 8 by cover tiles 9, having grooves 10, 10 which engages the rods and preserve their alinement. These rods are preferably formed of recrystallized carborundum (biC) and the spaces between them are filled with broken pieces ofithe same material, as r, Fig. 2.

' Along the sides of the rods are two galleries 13, B- whose outer faces may be formed by the furnace walls 12, 12. These galleries constitute the reaction chambers and receive the charge-material P. Beneath the resistor grate bars is the condenser J, Fig. 1, which is provided with a system of spaced grate bars 13 forming a grating or perforated hearth located over a bath of liquid zinc 1 1 and on which hearth is located a carbon filter bed G. Right and left hand ports 15 and 1G connect the spaces between the grate bars with sub-divided right and left hand chambers D, D and T, T having tubes 17, 17 leading to the atmosphere. The lower sub-divided chamber N, N is for supplying either fuel, heator cold air, as may be re quired for controlling the temperature of the zinc bath.

The operation is as follows: The charge is supplied through slots 18, 18 which may be narrower than the width of the galleries and they may be covered as by the plate 19 or left open and sealed with the chargematerial which is preferably also spread ove'rthe top of the resistor cover as denoted in Figs. 1 and 3. \Vhen the galleries are first filled, the charge will be in direct contact with the upright rods and some portions of the material may also be in direct contact with the resistor between the rod spaces in which case the reaction will proceed by conducted heat. The immediate cifect of the reaction isto eat away the face of the charge after which the disintegration will thenafter to a certain'extentbe caused by radiant energy received both from the rods and the As portions of the charge material in the galleries may fall down to more or less fill the s ace or spaces that have been exhausted tiere may be periods when the reaction proceeds rows 22.

fume and monoxid of carbon. The escape of the vaporized products of. the reaction is in a horizontal direction, through the rod spaces,'directly into the interstices of the incandescent resistor carbon thence down through the grate bar spaces, as in the direc tion indicated by arrows 20, to the equalizing chamber e then on through the filter bed, the condensed Zinc gravitating to the bath as indicated by arrow 21 and the CO passing into the chambers as indicated by ar- It will be perceived that it any pernicious oxidizing agent, such as CO results from the primary react-ion it will be elimiirated by the secondary reaction which is produced in passing through the resistor. As a consequence ofthis only clean Zincfume and pure CO will be delivered to the filter bed whose function thereby becomes that of an absorbent and conductor of heat and to facilitate the coalescence of minute spheres of zinc into a collected mass of liquid metal. As stated, the vertical rods are preferably formed of a material more or less electrically non-conductive and also of a character which is immune to the effects of the reactions. 2

Attention is directed to the fact that all of the heat emitted by both of the vertical longitudinal sides of the resistor is entirely util- -ized for useful effect, that if the resistor cover is coated with reserve charge material such an amount of heat as may pass upwardly through the cover will be largely utilized in pre-heating the said reserve materials; and that the heat conducted away from the'bottom ot' the resistor will be minimized by the counter-efi ect of the hot fume and gas within the grate bar spaces and the underlying chamber; consequently, the thermal etlieiency of this design and construction a bed of carbon resistor is of very high order. As shown in the drawn this disposal and arrangement of the resistor makes it quite feasible to readily stack the broken carbon with large pieces along the sides and a central core of smaller pieces, or that they shall progressively increase in diametrical dimensions from the center ri 'it and left, to the sides. in this wise, tln atcr current density will be precisely t the faces where the flow of calories are mmt needed.

scraped tln ough suitable open] ends.

In a sense, the resistor is Buried in the chargeaetually so to the extent of, its vertioal side-faces and top, yetit is adequately insulated therefrom so that useless dissipation of electric current is avoided.. Then t'he inert residual matter does not and cannot come into contact with the carbon resrstor.

This avoids the clogging of the resistorandpermits a continuous operation over 'a long period and with a practically uniform rate of production. When it may become necessary to renew portions of the resistor or substitute it with a new one it is obvious that this can be readily and quickly done.

lVhile the employment of the vertical rods for confining the sides of the resistor is deemed preferable still they can be dispensed with as is shown on the right hand side of Fig. 3. Here they are substituted by an outer course of relatively large broken pieces as 25, formed of comparatively electrically non-conductive and reactively immune material, such as earborundum, the inner courses being of carbon. Also the fixed furnace walls 12, 12, shown in Figs. 1 and 2,

may have substituted therefor heavy steel channels 26, 26 filled with fire bricks 27, as shown in Fig. 8. The ends of the channels project beyond the end walls of the furnace and are coupled by threaded tie-rods 28 having nuts 29, 29. Thus the side walls are movable to or from their position at the sides of the resistor. The advantage of this arrangement and construction is that the charge material can be forced into the'continnous contact with the resistor, whereby its heat acts upon. the charge entirely by conduction. There is also a contingent advantage which consists in being able to somewhat compress the component parts of the charge; consequently, as'is well known, the greater the intimacy of contact between re acting materials the more rapid and intense may be the rate of the reaction. Again, when .the laterally movable walls will have been forced forward'to whatever may be the limit of their movements, the galleries thereby reaching their minimum widths, they are then withdrawn outwardly and this will leave clear spaces at the rear ot' the material under reaction into which the fresh charge material is inserted. The result thereof is that cold materiahneed never be brought into direct contact with the incandescent far s of the resistor, whencethe rate at the re. ion may be continuedwiththe utn'tost uniformity. Finally the sumps may he made wider and by lifting oil the cha \nel sidewalls the residue can be very qt "ikly as denoted by the flow arrows. This con tral gallery is blanketed by right and left hand galleries as 31, 31, and 32, 32 and 33, 38", formed by septa or plates as 34. These septa have various transverse ports or openings arranged along their lower and upper portions as 36 and the lower ends of at least partare immersed in the bath of liquid zinc 1 L. It will now by .-.pparent that fume and -.gas must alternately flow down and up, each downfloW, impinging upon the bath, and that zinc condensed in any of the chambers must necessarily gravitate either through space or along the sides of the septa to the liquid zinc beneath. The residual gas finally finds atmosphere through tubes, 37, 87*, situated at or near the upper portions of'the two outer galleries 33, 33*. There are also two flues 38, 38 disposed along theoutsides of theaforesaid outer galleries into which either fuel heat or cold air may be introduced as maybe desired.

According to the foregoing arrangement and construction, the fume and gas are caused to flow at a relatively low velocity through galleries and along the sides of par- 'titions which become progressively cooler both at their bottoms and right and left of the center.. Moreover as the zinc fume "condenses out'of the monoxid of carbon and .as the volume of the latter, through dimi- .nntion of lts temperature, becomes progressively less, the velocity in the outer gallery ist muc-h diminished whereby every opportunity-especially as to time is afforded the fume to precipitate, therefore, theback pressure atthe seats of the reaction becomes negligible. The liquid zinc may be tapped off fromanyor all of the galleries and they can also be readily reached through suitable end openings for, scraping or cleaning if such is required. Thus if the rate of evolution of fuirxeisianore rapid than the condenser can liquefy, cold air can be circulated through the fines so that the temperature within the outergalleries Will be reduced. below thefreezing point of zinc whence the fume which reaches these galleries may be chilled and precipitated in the form of blue-powder, either to'flovv out with the fluid metal or to be removed by scrapers,

- according to circumstances;

The improvements herein set forth are not limited to the precise construction and arrangement shown and described and they may be embodied in various forms andmodifications without departing from the spirit and scope of the invention, as for example, the vertical rods may be substituted by a tamped casing rovided with numerous slots, slits or per orations and instead of a single condensingunit a plurality thereof may be employed whereby to obtain any capacity that may be required.

What I claim is:

1. In an electric zinc furnace a bed of carbon resistor whose lower surface rests on a grate and whose side surfaces are retained by spaced rods.

2. In an electric furnace a bed of carbon resistor which when the furnace is in operation is'embedded in a charge of reacting material, the said resistor being suitably supported by a grate or hearth and the furnace having sides which are formed of or sheathed with material immune to the effect of the primary reaction.

3. In an electric zinc furnace a bed of carbon resistor resting upon a grate or per forated hearth with a reaction chamber disposed along the side of the said resistor.

4. An electric Zinc furnace having a bed of carbon resistor suitably supported by a grating or hearth and constructed and arranged so that when the furnace is in op eration the charge of reacting materials will be disposed along the sides of the resistor and so that the reaction will occur primarily along the vertical sides of the resistor.

5. In an electric zinc furnace a carbon resistor adapted to act either by conducted heat or radiated heat or both upon chargematerial disposed along the vertical sides of the said resistor.

, 6. An electric zinc furnace having a bed of carbon resistor, along the sides of which the charge material is disposed when the furnace is operating, the side faces of the resistor being sheathed with or retained in place by spaced material or members having an electrical conductivity less than that of carbon.

7. An electric zinc furnace having a bed of carbon resistor, along the sides of which there is disposed a charge of reacting materials, the reacting materials also being located above the upper surfaces of the resistor, the side faces of the resistor being sheathed with spaced or broken material and its top being inclosed with comparatively non-conductive tiles or bricks.

8. In an electric zinc furnace a bed of .carbon resistor arranged and constructed to act upon charged-material disposed along its sides, said resistor being constructed so that its current-density is greater in the zones contiguous to the sides where the reaction is produced.

9. In an electric Zinc furnace, a bed of carbon resistor, arranged and constructed to act upon charged-material disposed along its side, said resistor being constructed so that current-density increases progressively from its vertical center plane toward the side along which the charged-material is disposed.

10. In an electric zinc furnace at bed of I carbon resistor supported by a grating or lheartli and acting upon charged-material disposed along its sides, the volatilized products of the reaction passing into the said resistor while the inert or residual products of the reaction precipitate into outside sumps.

11. In an electric zinc furnace, a bed of carbon resistor, supported by a grating or hearth and acting upon charged-material disposed along its sides, the volatilized products of the reaction entering the said resistor in a horizontal direction and thence passing downwardly toward the said'spaced grating or hearth. v v

12. In an electric zinc furnace, a bed of carbon resistor, Whose zones of reaction are along its vertical. sides, and laterally movable side walls. V

13. In an electric furnace a bed of carbon resistor with which a'charge of react-- movable walls the width of said chambers bers of galleries disposed along the vertical being increased or decreased said walls.-

15. In an electric zine furnace a bed of carbon resistor having reaction chamsides of the resistor, sumps at the bottoms by moving of the-said chambers and outer walls adapted to be removed whereby the residue may be withdrawn sidewise from the sumps.

16. In an electric zinc furnace a bed of carbon resistor suitably supported by a spaced grating or hearth, reaction chambers disposed along the sides of said resistor and a condenser, or condensers, adaptedto receive the volatilized products of the reaction as and when educted through the said grating or hearth.

17. In an electric zinc, furnace a bed of carbon resistor suitably supported by a spaced grating or hearth through which the volatilizedproducts of the reaction are educted and a condenser comprising a bath of molten zinc, a central receiving chamber and a plurality of right and left hand galleries through which the fume and gas are caused to traverse in series, alternately ascending from the bath. and then descending toward it.

18. An electric zinc furnace characterized by a bed of carbon resistor whose re action zones are disposed along its vertical sides, a spaced grating or hearth upon which the said resistor is sustained, residue-sumps disposed along the sides and bottom of the said resistor, and a condenser or condensers adapted to receive the volatilized prodnets of the reaction from the said resistor and thence educting them through the spaces of the said grating.-

This specification signed and witnessed this 31 day of December A. D. 1912.

-- JOHN THOMSON,

Signed in the presence of-- EDWIN A. PACKARD,

D. HAnoLn BUSH.

Copies of this patent may be obtained'for five cents each, by addressing the Commissioner of Patents.

Washington, I). G. 

